Background Mallet fracture can easily occur during sports activities or in daily life; however, the principles and methods of treatment for such fractures remain debated. Among the surgical treatments, various methods of closed reduction have been proposed. We treated patients with the extension block method (EBM) and the direct pinning method (DPM), and then compared the results. We assessed differences in range of motion and measurements of finger movement after surgery. Methods A total of 41 patients who underwent surgery from August 2013 to September 2015 were evaluated retrospectively. Among them, 21 patients were treated with the EBM and 20 patients were treated with the DPM. We then compared extensor lag, range of motion, and outcomes according to Crawford’s criteria between before surgery and at 6 to 8 months postoperatively. Results The postoperative extensor lag improvement was 4.28° and 10.73°, and the postoperative arc of motion was 55.76° and 61.17° in the EBM and DPM groups, respectively. The Crawford assessment showed no statistically significant difference between the groups, although the score in the DPM group was higher than that in the EBM group (3.5 vs. 3.1). Conclusions As closed reduction methods for the treatment of mallet fracture, both the EBM and DPM showed good results. However, the DPM proved to be superior to the EBM in that it produced greater improvements in extensor lag and range of motion.